George WeigelSpring and summer are the two best times to prune evergreens. Fall is worst.

Q: I do most of my pruning in the spring but am wondering about pruning in the fall. I'm thinking about trimming the boxwoods and hollies. After growing all summer, they get unsightly and unkempt looking. Can I safely prune them before winter so they don't look bad in the fall/winter months? If so, when is the best time to do it?

A: Fall is the worst time to prune evergreens.

Two reasons: 1.) If you prune in early fall, that could stimulate new growth that won't harden off in time and then get damaged at the first cold snap, and 2.) If you wait until after that point, any bare wood and cut tips you expose will stay that way all winter until new growth in spring starts to hide them.

So either way, it's not a good time.

A much better time to prune boxwoods and hollies is at the tail end of winter and early spring – late March through April. At that time you can first take care of any winter damage, then do your size-control and/or shaping at a time when new growth will quickly fill in any chopped look.

You can also continue to neaten throughout spring, early summer and mid-summer (except in drought). Knock it off by Labor Day and let your plants begin to go dormant. If you've kept them the way you like them in with spring and summer pruning, they won't be growing much more from then on and will look fine all winter.